Thermochemical Surface Engineering of Stainless Steels With Interstitials; Symbiosis of Science, Technology and Innovation

Thermochemical surface engineering of stainless steels with carbon and nitrogen atoms was originally considered bad practice, because these elements would readily bind to chromium and thereby compromise the stainless character of the steel. The 80-ies and 90-ies of the previous century saw the introduction of low and high temperature routes for thermochemical surface engineering of stainless steels, without the formation of chromium carbides/nitrides.

These routes are currently known as low temperature surface hardening (LTSH) and high temperature solution nitriding (HTSN), respectively. The present contribution addresses the scientific understanding, the technological feasibility and the innovative materials solutions related to dissolving interstitials in stainless steels.

This is illustrated with examples from our own research group and combines experimental and numerical approaches.